Copy both the image file, they are stored someplace on your older computer hard drive, and the older LR versions Catalog file to an external drive of some type. Then copy them off the external drive to your new computer. Open LR and point it to the catalog file you copied over and the newer version of LR will make a copy of the catalog file and upgrade it to work with the newer version of LR.

The images should be place in the same folder structure as they were on the old computer. Drive letter or name and in all the same folders.